Oh my god, I went through the exact same thing!
After reading the glowing critical reviews, I went to see it with half a dozen pals (everyone had read the books, but me) and they all came out raving about the great story and characters and here I am, a huge movie buff who knows quality, who didn't really care for it. Sure, great special effects, awesome sound, some interesting battles, some amazing sights, but I just wasn't moved by the characters. Also, the plot is impenetrable on a book-virgin's first viewing. I didn't know what the hell was happening to whom. Also, at 3 hours, it was 2 hours too long.
Thank you for coming clean. I feel so relieved.